1. Field of the Invention
The present invention relates to heat recovery systems and, more particularly, is directed towards textile dryer heat recovery systems.
2. Description of the Prior Art
In the manufacture of textile products, a padder is used for applying a particular finish or finishes to fabrics in the form of coatings or impregnations in order to impart specific characteristics to the fabrics. Then, the treated fabric is fed to a textile dryer which is fired by coal, oil or natural gas. The exhaust gas from combustion of coal, fuel oil and natural gas contains moisture, sulfur compounds and particulates. In one type of heat exchanger, which is used for devices having a corrosive exhaust gas, the internal surfaces through which heat transfer takes place are coated with a tetrafluoroethelyne polymer in order to provide protection from sulfuric acid corrosive attacks within specific temperature limits. In addition to combustion products, the exhaust gas from the textile dryer contains contaminants such as dye residue, wax, oil, condensates and lint. Attempts to use heat exchangers with textile dryers have not been successful because the contaminants in the exhaust gas rapidly coat the heat exchanger surfaces through which heat transfer takes place. This coating of contaminants prevents efficient preheating of the textile dryer input air and renders the heat recovery system relatively useless. A need has arisen for an efficient heat recovery system for textile dryers.